15-3

Gas Lab Stations<---Previous Assignment - Next Assignment--->

Time Length

• 2 Days

Instructions
Follow the instructions at each station listed below. Take a computer around with you and answer the questions on a new wiki called 15-3 Gas Lab Stations

Lab
Activity #1: Egg in a Bottle
In this activity you will be observing the affects of pressure and temperature on a hardboiled egg. Remember that pressure always flows from high to low pressure.


Procedure:

1. 1. Light a scratch piece of paper on fire and immediately put drop it into the Erlenmeyer flask and cover the top with the hard boiled egg.

1. 2. When the match goes out, what happens to the egg? Record Observation.

1. 3. To get the egg out of the bottle when done, turn it upside down and pour boiling water on the top over a brown bin.

Questions:

1. As temperature decreases, does the pressure of the gas increase or decrease?? Draw your arrows!

1. What happens to the pressure inside as the flame goes out? How could this relate to why the egg was sucked in to the bottle?

1. Explain what you just saw using a gas law explanation! *Think about, what increased, or what decreased?
   Activity #2: Marshmallow in a Syringe

In this activity there is a mini-marshmallow trapped in it. Marshmallows contain a lot of air pockets and by observing what happens to the marshmallow you can determine what happens to the air trapped within it.

Procedure:

1. Take the plunger out of the syringe and place a fresh marshmallow into the syringe.
2. Replace the plunger and push the plunger down to the 20 mL mark.
3. Seal the other end of the syringe using your thumb. Be careful that you form an air-tight seal.
4. Press down on the plunger. Look closely at the marshmallow. What is happening to it? Observations:

1. Release the plunger. What happens to the marshmallow?

Observations:

1. Push the plunger down to the 20 mL mark again.
2. Seal the other end of the syringe using your thumb again. Be careful that you form an air-tight seal.
3. This time pull the plunger out. Look closely at the marshmallow. What is happening to it?

Observations:

1. Release the plunger. What happens to the marshmallow?

Observations:

Questions:

1. What variables (2) are we manipulating with this activity? (pressure, volume, temperature) Explain.

1. What variable is being held constant? (pressure, volume, temperature) Explain.

1. a.) What happens to the pressure inside the syringe as you push in the plunger?

b.) What happens to the size of the marshmallow as you add push on the plunger?

1. a.) What happens to the pressure inside the syringe as pull out the plunger?

b.)What happens to the size of the marshmallow as you pull out the plunger?

1. What is the relationship between the volume (size) of the marshmallow and the pressure inside the syringe? Draw your arrows!

P V







Activity #3: Candle Lab

In this activity you will observe what happens when you place a glass over a burning candle that is sitting in a dish of water.
Procedure:

1. 1. Light the candle, invert (flip) the beaker over the candle setting the glass mouth down into the water. Carefully observe what happens. You need to be eye level with the candle.
2. 2. You may have to repeat the procedure several times. Draw what you see.
3. 3. There are two candles at this station, if time, you can experiment with how much water you place in the dish to see if that affects the results.

Observations: Draw a picture of what you observed.








Questions:

1. Describe the gases pressure in the beaker while the candle is lit. Draw in your arrows!

T P

1. Now describe the gases pressure above the flame when the candle goes out. Draw in your arrows!

T P


3.) On the diagram below, which beaker has low pressure on the inside??? Write LOW P in the correct Beaker. Write high P on the outside of that beaker. Then draw arrows to expain why the water when up! Give a brief statement explaining why!





Activity #4: Balloon on a Flask

In this activity you will observe what happens to the air within a flask as the temperature of the flask is changed.

Procedure:

1. 1. Take a balloon and place it on a flask at room temperature. Describe what you see

Observations:

1. 2. Now take the flask over to a hot plate and place it in a beaker of boiling water.
2. 3. Let the flask sit in the water for a few minutes. Be Careful not to burn yourself.
3. 4. What happens to the balloon as the flask is heated? Describe what you see .

Observations:

5. Now take the flask and place it in ice water. Let it sit for a few minutes
6. What happens to the balloon as the flask is cooled? Describe what you see and draw a picture.
Observations:




Questions:

1. What variables (2) are we manipulating with this activity? (pressure, volume, temperature) Explain.

1. What variable is being held constant? (pressure, volume, temperature) Explain.

1. What happens to the volume (size) of the balloon as the flask is heated?

1. What happens to the volume (size) of the balloon as the flask is cooled down?

1. What is the relationship between the volume (size) of the balloon and the temperature of the gas inside it? (As temperature increases/decreases, the volume of a gas increases/decreases)

Activity #5: Dancing Coins

In this activity you will observe what happens to a coin when it is placed on top of a glass bottle.

Procedure:

1. Take a glass jar from a container of ice water.
2. Dry the outside of the glass jar…it is ok to have a little water inside of the container.
3. Wet your finger with water and run it along the top of the jar.
4. Place a penny on top of the jar…the water should form a seal.
5. Rub your hands together to get them warm.
6. Wrap both hands around the bottle and hold it …what happens? Be careful not to disturb the penny and break the seal.

Observations:

1. How many times can you get it to happen just by holding the jar? Take turns with your lab partners rubbing your hands and holding the container.

Observations:



Questions:

1. How did rubbing our hands affect our experiment?

1. Why does the penny move? Explain.

1. At a constant volume, as temperature increases, the pressure of the gas (increases / decreases)

1. Explain why water doesn’t boil at 100 °C on top of a mountain!

Activity #6: Crush the Can

In this activity, you will use the properties of gasses to crush a can.

Procedure:

1. Pour about 10 mL of water into a soda can and heat it until the water boils. You should be able to see steam leaving the can.
2. Quickly turn the can over and submerge the top of the can into cold water using a pair of tongs.
3. What happens?

Observation:




Questions:

1. As temperature increases, the gas pressure inside the can (increases / decreases)

1. As temperature decreases, the gas pressure inside the can (increases / decreases)

1. Why does the can crush? Think about what happens to the pressure inside the can as the temperature decreases. The air pressure outside does not change.